This invention relates to a system and method for the efficient coupling of radiation between optical devices and more particularly from a radiation source to a waveguide.
When coupling the output of a laser, such as a vertical cavity surface emitting (VCSEL), or a multimode optical fiber into a thin waveguide (e.g., a planar waveguide or an optical fiber), there may be large and unacceptable mode and size mismatches between the laser output mode and the modes that can be supported by the thin waveguide. These mismatches lead to correspondingly large radiation losses between the optical components. Until now these significant losses have been ignored or overcome by simply increasing the output power of the VCSEL so that a desired amount of energy is coupled into the waveguide.
In the new generation of opto-electronic components one key factor is the size thereof. On the one hand power must be limited to the minimum possible, while on the other, high power is desirable to guarantee good performances such as speed (or bandwidth) and signal/noise ratio. Thus, any power loss is at the expense of device performance. In addition, thermal and cooling issues arise at higher powers. Also, the lifetime of the VCSEL may be impaired if it is overdriven. Yet further, nonlinear or abnormal behavior such as undesired noise, distortion of output signals, etc. may result when a VCSEL has been overdriven.
Thus, there accordingly remains a need in the art for a system and method for the efficient coupling of radiation from a radiation source to a waveguide, or other optical component, without suffering excessive radiation losses at optical interconnections.